NRF51822 ADC

RE: NRF51822 ADC

Jørn — Fri, 24 Mar 2017 12:45:42 GMT

If you wish to do a test of the radio you can use the radio_test example found in the examples->peripheral folder of the SDK. It allows you to test different frequencies, powers, datarates, modulation etc. More information on the example can be found at

infocenter.nordicsemi.com/.../nrf_radio_test_example.html

Information about frequency and channel selection can be found in the radio registers description, page 93 of the nRF51 series reference manual.

RE: NRF51822 ADC

zcmm — Wed, 22 Mar 2017 10:43:02 GMT

Test frequency deviation is must send by carrier（ such as DTM exmaple bin file） or can use GSFK modulation test（such as beacon exmaple file）？

RE: NRF51822 ADC

Jørn — Tue, 21 Mar 2017 14:13:17 GMT

I'm sorry, I'm not quite sure what you're asking. Could you please elaborate on your question?

RE: NRF51822 ADC

zcmm — Tue, 21 Mar 2017 08:15:56 GMT

thanks,it is my question.
i have a other question.In addition to DTM bin, I can also use other routine test frequency,like beacon?

RE: NRF51822 ADC

Jørn — Tue, 14 Mar 2017 13:33:40 GMT

Hello zcmm

You mention bandgap in your question, but I see you have used the supply prescaler. I will assume you have NOT used the bandgap voltage (VBG) as reference, but prescaled versions of the supply voltage VDD. Please correct me if this is wrong.

As the product specification states VDD should be within 1.7-2.6 V when using 1/2 supply prescaler, and between 2.5-3.6 V when using 1/3 supply prescaler. If VDD is outside these ranges accuracy and performance cannot be guaranteed. This is the case in your final 1/3 prescaler set-up, and it is therefore not possible for me to comment on the results you get as the effects of operating outside the specified ranges is not documented.

The specific value for VDD you have, as well as any voltage scaling network you may have outside the ADC, can greatly affect the result you achieve. This makes it difficult for me to assess the results you have without knowing more about your system. How prescaling and voltage dividers affect ADC performance and results is described in the nRF51 series reference manual infocenter.nordicsemi.com/.../nRF51_RM_v3.0.1.pdf

I suggest you take a look at the ADC chapter in the reference manual, and ensure that you are operating within the specified voltage ranges, and have taken external circuits into consideration.

Best regards

Jørn Frøysa